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Ennovi CCS Could Lighten EV Battery Packs

June 03, 2024 by Jake Hertz

The company’s advanced lamination methods could boost EV battery manufacturing efficiency, reliability, and sustainability.

At the heart of electric vehicle (EV) battery systems lies the cell contacting system (CCS), an assembly connecting individual cells to form a cohesive energy source. Traditional CCS processes, however, introduce challenges such as increased weight and complexity, which can hamper vehicle performance. Optimizing the CCS can lead to lighter, more reliable, and easier-to-manufacture battery modules. 

Ennovi has unveiled an innovative lamination approach for CCS assembly. The method could overcome the limitations of conventional CCS assembly and enable lighter, more cost-effective EV battery packs.

 

Example of electric vehicle battery pack.

Example of electric vehicle battery pack. Image used courtesy of Adobe Stock

 

The CSS Assembly

An EV battery pack includes current collectors, anode and cathode, electrolyte, separator, and casing. 

Current collectors, usually thin metal foils, support electrodes in individual cells. In battery modules, these collectors are assembled into layers or plates, known as current collector assemblies (CCA), to combine the power of multiple cells into a single output. A grid-like holder with the collector plate and busbar on top holds the cells. 

CCS assembly assets include battery capacity, rate capability, electrochemical stability, electrical conductivity, mechanical properties, density, and sustainability. These factors determine the energy handling capacity, discharge rate, stability of energy exchange, flow rate of electrical energy, environmental stability, energy density, and recyclability of CCA components, respectively.

The conventional CCS assembly process in batteries utilizes molded plastic trays and foams. Initially, molded plastic trays accommodate individual battery cells, offering structural support and electrical insulation. Foams are inserted within the trays to firmly secure and cushion the cells, ensuring mechanical stability and optimizing thermal regulation. This method enables the precise cell arrangement and alignment within the battery pack, facilitating efficient energy transfer and enhancing overall performance. 

While efficient in cell and collector placement, these techniques add unwanted weight and intricacy, particularly with larger module sizes in EVs.

 

Simplifying CCS Complexity 

Ennovi’s advanced CCS lamination approach circumvents cumbersome practices like molded trays and foams. The company introduced hot and cold lamination processes to enhance precision without the constraints of traditional methods. 

Heat and pressure can cure and set the adhesive layer in hot lamination, whereas cold lamination relies solely on pressure. Although hot lamination is more expensive, requires additional production steps, and has longer cycle times than cold lamination, the final product’s quality and durability for targeted applications remain the primary determinant. Ennovi provides all three methods—plastic trays and hot and cold lamination—to cater to customers’ varied EV and battery manufacturing requirements. 

 

Ennovi’s new CCS method.

Ennovi’s new CCS method. Image used courtesy of Ennovi

 

By meticulously testing PET insulation foils and adhesives, Ennovi ensured optimal bond strength and durability, eliminating the need for trial-and-error-based material selection. As CCS designs transition from bulky plastic trays to advanced lamination methods, battery manufacturers can cut costs, produce thinner CCS, and uphold precise tolerances to accommodate larger battery packs.

 

Driving the Future

Ennovi says the innovation offers improved flexibility and efficiency to global original equipment manufacturers and tier-one suppliers, ultimately optimizing structural integrity, lifespan, and manufacturing cycle times. With the new lamination approach, Ennovi prioritizes durability, flexibility, and cost-effectiveness to create higher-quality, longer-lasting CCS current collectors.